In recent years, an organic electroluminescent device (OLED), as a new type of flat panel display apparatus, attracts more and more attention gradually. It will become a next generation of display technology that may replace the liquid crystal display for its characteristics, such as self-illumination, high brightness, high resolution, wide viewing angle, fast response, low power consumption and flexibility or the like. But, an organic layer material in an OLED, is extremely sensitive to water vapor and oxygen, so that the service life of the OLED is greatly decreased. At present, to solve this problem, a method is often used to isolate an organic device from external space by various materials. However, conditions of water vapor and oxygen specifically required in a sealed space that this method needs to satisfy are relatively high.